What have I got here?

[Gerry M]

This is an older (I think) Beseler 23C2 head that was with some other enlarger gear that I bought. My question is concerning the sliding device on the side of the housing that holds the lens board. It slides left to right, and it has what looks like a piece of plexiglass that opens or closes the light source. I have two other 23C2's that don't have this device. So, the big questions is; what is this mechanism for?
Thanks,
Gerry

 

[Rick A]

Thats for a red filter. Peel the covering off and it should be red plexi.

 

[Gerry M]

Rick,
So, that takes the place of the lower mounted, swinging filter holder on the newer models?
Also, you can see that there is a hole bored in the lower left corner of the plexiglass. What would be the purpose of that?

 

[J Rollinger]

I have the same thing on my Beseler 4x5 enlarger and also was wondering what its for? At first i thought it was to focus while the paper was in but it has a hole in it. My enlarger has a drawer for 6in filters.

 

[Rick A]

I have a feeling that is the wrong red filter for that negative stage. That looks like the plexi for a Printmaker or the 67, which use a swing away filter.

 

[J Rollinger]

That makes sense that it would be for a swinging holder but why would they include the plexi one with the hole and not a solid one for the enlarger.

 

[Gerry M]

Here are some more views of the device.

It almost looks as if this is an after market item. When it is pushed in, it closes off the light source, or with the paper covering removed would be a filter. You can see that the protective paper cover has never been removed. I think the plexiglass is red, but have not peeled the paper back.
The knob design on the tray doesn't match any other knobs on the enlarger.
I have two other, newer 23C2 heads and the lower bellows on these are glued down. On this older head, it is screwed to the casting that holds the lens board. It has the regular compartment for ~5.5"X5.5" filters, but no swinging tray.
The last image is of a newer housing with the swing away filter tray.

 

[Rick A]

Like I said, there shouldn't be a hole in the plexi, it rests in the tray. The handle slides it across the light path or out of the way. I'll get photos of one of mine tomorrow and post them here.

 

[John Koehrer]

Does the hole align with a light pipe to illuminate the f stop?

 

[ic-racer]

Good thought. The green numbers on some lenses don't do so well with red light

 

[J Rollinger]

John got it right, the hole lines up with the light pole.

 

[Gerry M]

Well, in my case, the hole does not line up with the light pole. I removed and rotated the (filter?) insert. In the first series of photos, the opening in the casting measures 2.25" X 2.25" and the flange blocks the light pole. . On my other 23C2's this opening is 3" X 3" and the light pole is unblocked. I still think this may be a special housing (maybe for 6 x 6 production?).

 

[J Rollinger]

Did you try turning and flipping the filter to see how it lines up with the light pole in all of the 4 possible positions?

 

[Gerry M]

Did you try turning and flipping the filter to see how it lines up with the light pole in all of the 4 possible positions?

Yes, I rotated it 360' One problem is the flange that creates the 2.25" square opening covers the light pole. I would really like to know what this set up is/was for. As I said, I have two "normal" 23C2's, but this one is a mystery to me.
Gerry

 

[Luseboy]

The idea is that you turn your enlarger into a safelight so you can put your paper in well. Personally, i took the red plexi out, and i use that drawer for filters on both my 23c2 and my 45mxt. Works great. I've never used the red filter, but i've heard bad things

 

[Ian C]

That’s the older slide-in red “Safety filter” holder. Later Beseler simplified the casting and installed the much simpler (and much cheaper to make) sheet metal holder that swings into and out of position under the lens.

The change must have taken place during the production of the 23C II version because I have one with the slide-in filter, while the other two have the simpler pivoting filter holder.

The slide-in holder is mainly for the red filter. You’d use the filter slots above the condensers for VC or CP filters, or you could use a clamp-on holder for below-the-lens filters. However, the manual states that VC filters could be fitted to the slide-in holder if wanted.

See pages 5 and 11 of this PDF. On page 12 the use of VC filters in the above condenser slots is discussed.

Dead Link Removed

 

[Gerry M]

Well, the mystery is solved. It seems that on the very early production 23C II XL's, the earlier production 23C lens housings (blue type) were used and just painted black by the factory. Thanks to all for your input.
Gerry

Ian, Thanks for the link.